1. Field of the Invention
The invention relates to a roll support structure of a printing device. More particularly, the invention relates to a roll support structure of a printing device, which allows a fountain roll and the like to be attached and removed with little effort, and which can respond to a change in printing conditions without difficulty.
2. Description of the Related Art
In a known flexographic press, a plurality of printing devices is disposed along the direction in which printing paper is fed. Each printing device transfers ink of a different color to printing paper, whereby polychromic printing is performed. Each printing device includes an ink pan, a fountain roll disposed such that an outer peripheral surface thereof faces the interior of the ink pan, an anilox roll contacting the outer peripheral surface of the fountain roll, a plate cylinder to which ink is transferred via the anilox roll, and a platen that faces the plate cylinder. Printing paper is supplied and fed between the plate cylinder and the platen, whereby predetermined printing is performed on the printing paper.
A gear is provided on one end side of each of support shafts of the above-mentioned fountain roll and the anilox roll. The gears on both the support shafts constitute an interlocking mechanism. One of the gears is engaged with a gear fixed to an output shaft of drive means including a motor and the like. Thus, when the motor rotates, the fountain roll and the anilox roll are interlocked with each other so that they can be rotated.
However, when the fountain roll is replaced by another fountain roll for changing the color of the ink filled in the ink pan, the above-mentioned gear needs to be removed from the support shaft. Thus, there is the inconvenience that an extensive operation is required. In addition, when the density of the plate for printing is changed, the anilox roll needs to be replaced by another anilox roll whose outer peripheral surface has a different finishing accuracy. In this case as well, there is the inconvenience that similar extensive operation is required.
These inconveniences result from use of the single motor constituting a drive source, and the mutual interlocking mechanism including the gear group transmitting the driving power of the motor.
In view of the above-mentioned inconveniences, it is an object of the present invention to provide a roll support structure of a printing device, which allows a fountain roll and the like to be replaced very easily and quickly, thereby facilitating roll replacement or maintenance and checking.
In order to achieve the above-mentioned object, the present invention provides a roll support structure of a printing device including a fountain roll disposed such that an outer peripheral surface thereof faces the interior of an ink pan, an anilox roll disposed so as to contact the outer peripheral surface of the fountain roll, a plate cylinder to which ink transferred to the anilox roll is transferred, and a platen disposed to face the plate cylinder.
The roll support structure of the printing device has a construction in which one end side of a support shaft of the above-mentioned fountain roll and/or the anilox roll is removably coupled to a rotating shaft for transmitting a predetermined rotating force, while the other end side thereof is supported via urging means that is movable in the axial direction. In this construction, the fountain roll and/or the anilox roll can be attached and removed very easily. Accordingly, when the color of the ink is changed, or when the roll is replaced by another roll for changing the printing accuracy, the efficiency of the operation can be significantly improved.
In the present invention, the construction may be such that one end side of the above-mentioned support shaft and the above-mentioned rotating shaft are coupled together via coupling means. In the construction, the coupling means includes a first coupling member fixed on the outer periphery of the above-mentioned support shaft, a second coupling member fixed on the outer periphery of the above-mentioned rotating shaft, a coupling hole formed in any one of the first and the second coupling members, and a shaft member which is fixed to the other of the first and the second coupling members, and which is fitted into the above-mentioned coupling hole. Accordingly, when the fountain roll and/or the anilox roll is removed, the coupling can be released by the operation of separating the above-mentioned support shaft and the rotating shaft such that the shaft member is pulled out of the coupling hole.
In addition, it is preferable to employ a construction in which the above-mentioned urging means includes a moving shaft that is movable in the axial direction, and in which the moving shaft and the above-mentioned rotating shaft each have a cone-shaped portion at the tip, which can be fitted in an end surface of the support shaft of the above-mentioned fountain roll and/or the anilox roll. Thus, centering of the fountain roll and the like can be performed with high accuracy.
Furthermore, it is possible to employ a construction in which one end side of the above-mentioned support shaft of the above-mentioned fountain roll and/or the anilox roll is supported by a chuck. In the construction, the fountain roll and the like can be supported at one end side by a scroll chuck which is used in a lathe turning machine and the like. Therefore, the installation cost of the roll support structure can be reduced by employing a construction which uses a versatile existing structure.